Answer:
61 Inches
Step-by-step explanation:
<em>A foot is 12 inches. </em>
1. Multiply 12 by 5.
2. Add the extra inch.
<em>The stack of books is 61 inches high.</em>
You need an equation for the solutions and an equation for the acid.
Let x = amount of 20% acid solution
Let y = amount of 50% acid solution.
The equation for the solution:
You want a total of 12 liters, so
x + y = 12
The equation for the acid:
The 20% solution has 20% acid, so in x liters of the 20% solution, you have 0.2x liters of acid.
The 50% solution has 50% acid, so in y liters of the 50% solution, you have 0.5y liters of acid.
The combined solution is 12 liters of 30% acid, so it has 30% * 12 liters of acid = 3.6 liters of acid.
0.2x + 0.5y = 3.6
Now you solve the two equations in a system of equations.
x + y = 12
0.2x + 0.5y = 3.6
Multiply the second equation by 10:
2x + 5y = 36
Multiply the first equation by -2:
-2x - 2y = -24
Add the last two equations:
3y = 12
y = 4
Substitute y = 4 in the first original equation:
x + y = 12
x + 4 = 12
x = 8
Answer: 8 liters of 20% solution and 4 liters of 50% solution.
Answer:
You need to have an average speed of at least 35 miles per hour for the rest of the trip to get to the church on time
Step-by-step explanation:
We use the following relation to solve the question:
In which v is the velocity, d is the distance, and t is the time.
First 15 minutes:
Time of 15 minutes = 0.25 hour, so
Velocity of 5 miles per hour. So the distance is of:
Final 15 minutes:
The will need to drive 10 - 1.25 = 8.75 miles in 15 minutes = 0.25 hours. So, the average speed will need to be of at least:
You need to have an average speed of at least 35 miles per hour for the rest of the trip to get to the church on time
Answer:
Step-by-step explanation:
7.5 pounds divided by 14 days= 0.5357 pounds or 0.54